This invention generally relates to devices used to rejoin a human sternum that has been severed longitudinally, and more particularly relates to such devices that function in a clamping manner to retain the severed sternum portions in a closed and abutting relationship post-operatively.
It is often necessary in surgical operations to longitudinally sever the patient's sternum so that the ribs may be spread to provide access to internal organs such as the heart. It is then necessary to secure the sternum halves together for post-operative recovery. Various closure techniques are used to accomplish this task. For example, holes may be drilled into the sternum halves and suture material passed through and tightened to cinch the sternum halves together. Apertured plates may be added to further rigidify the sternum post-operatively, with the suture material being passed through the apertures in the plate and the sternum. Encircling members may be wrapped around the sternum and tightened. Toothed bridging members extending across the cut line may be pressed into the sternum surfaces and/or secured with threaded rods extending between the sternal halves.
Another sternal closure technique involves the use of clamps having hook-like projections or engagement members on both ends, the clamp being positioned laterally relative to the sternal incision with the projections being disposed between adjoining rib pairs on opposite sides of the sternum. The clamp is then linearly contracted or compressed to shorten the device and force the sternal halves together, the clamp typically comprising two members joined in a linearly telescoping manner. Locking or securing means, either permanent or releasable, maintain the clamp in the contracted configuration so that the sternum can heal.
Examples of such techniques and devices are described in U.S. Pat. No. 3,473,528 to Mishkin et al., U.S. Pat. No. 4,201,215 to Crossett et al., U.S. Pat. No. 4,279,248 to Gabbay, U.S. Pat. No. 4,583,541 to Barry, U.S. Pat. No. 5,139,498 to Astudillo Ley, U.S. Pat. No. 6,051,007 to Hogendijk et al., U.S. Pat. No. 6,217,580 to Levin, U.S. Pat. No. 6,302,899 to Johnson et al., U.S. Pat. No. 6,540,769 to Miller, III, and U.S. Pat. No. 6,712,821 to Gabbay the disclosures of which are herein incorporated by reference.
In certain circumstances, the strength and rigidity of the sternum may be insufficient to withstand the compressive forces of the sternal clamp, such that the sternum may be damaged upon compression of the sternal clamp or such that overtime the weakness of the sternum results in damage from the clamp. It is an object of this invention to provide a sternal closure clamp device having at least one rib extension member such that the clamp may be secured directly to the rib a distance away from the sternum, such that the compressive forces of the sternal clamp are dispersed between the sternum and the rib.